We had one as early as last year in one of the crossfit gym I train people at and even a year prior we had one to train hockey players, didn't really like it. If it is like what we had you can't really add enough resistance to make it even remotely close to a prowler.
It might be useful for Crossfit athletes because for some reason ($$$) they now have the motor-less treadmill runs at the Crossfit regionals so athletes would benefit from practicing on it.
But for other purposes it is not great. It didn't take long before the ones we had were abandoned and eventually returned.